This is our basic differential cover, we see it as the only one worth making. The D30 came in a few different trucks but it primarily came in Jeeps, from the Jeepster in the late 60's, through most of the CJ5, CJ6, & CJ7 years, throughout all of the different Wrangler variations (YJ & TJ) and the Cherokees (XJ). The D30 axle is actually a pretty good little axle if you don't get carried away with too big tires. One of the questions we get regularly is about the tie rod clearance, it is ~3/4" and it clears all of the D30 axle setups we have encountered. This is a 1 piece Plate steel cover bent 8 ways, way hard to hurt in .375 (3/8"). However, the ring on the D30 is 1/2", we had to make it thicker to make enough room for the thickness of the cover, it just happens to make it 30% stronger too! The fill plug is a generous 3/4" ID for easy fill and oil level check. This is arguably the strongest Diff Cover made for a Dana 30 axle. We manufacture this and all of our covers out of A50 Plate Steel, thats 50,000 PSI Tensile strength. After welding the mounting surface is machined absolutely flat for a perfect fit! This is for a fully welded D30 Differential Cover, welded inside and out with fill plug.